Chlorella protein hydrogel preparation and its application in loading and slow release of poly(lysine)

This article is dedicated to the preparation of a novel Chlorella protein hydrogel that can be used as a slow release carrier. Chlorella proteins and alginate were used as cross-linking agent at the present of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide/N-hydroxysuccinimide to obtain hydrogel with different 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide/N-hydroxysuccinimide concentration. Textural results showed that hydrogel with high N-hydroxysuccinimide concentration possessed good hardness, springiness, gumminess and chewiness, espasically those hydrogel with 23% N-hydroxysuccinimide concentration. Scanning electron microscopy results revealed that the prepared hydrogel with higher N-hydroxysuccinimide concentration had better stable spatial porous structures. Swelling analyses indicated the prepared hydrogel exhibited pH sensitivity, which were beneficial for the slow-release. Then the hydrogels with 23% N-hydroxysuccinimide were used to be poly(lysine) slow-release carriers. Moreover, this hydrogel exhibited a prolonged and efficient period of poly(lysine) slow release at pH 1.2 (30%) and 7.4 (95%) within 200 h, which were further proved by good antibacterial activity against Escherichia coli and Staphylococcus aureus. Finally, based on the above results, we simulated the mechanism of hydrogel formation and poly(lysine) loading and slow release. The results reveal that the prepared Chlorella protein hydrogels are beneficial for use as slow-release carriers.